adipic acid verbessert - n.ethz.chn.ethz.ch/.../praktikum%20oci%20(teil%201)/adipic%20acid.pdf ·...
TRANSCRIPT
Zurich, 06.12.2007
Synthesis of Adipic Acid
HO
OH
O
O
Tobias Langenegger [email protected]
05-918-362 D-Biol (chem.)
assisted by Guo Xiaoqiang
Method Oxidation of cyclohexanon with potassium permanganate to adipic acid. Chemical equation
O
KMnO4
NaOH
H2O
HO
OH
O
O Mechanism
O O
NaOH+ H2O
KMnO4
O
Mn7
O
O
OO+
O
Mn5O
O
O
O
O
O
O
H
- MnO3 + OH- -> MnO2
O
OH
O
OH
+ H2O
Mn7
O
O
OO
O
O
O
O
Mn
H
O
O
O
O
HO
OH
O
O
Mn5
O
O
OHO
H
Physical and safety data
substance Mw (g/mol)
density (g/cm3)
mp (°C)
bp (°C)
Poison
CH
R-phrases S-phrases
KMnO4 158.04 2.7 240 - 3 8, 22, 50, 53 60, 61
Cyclo-hexanone
98 0.95 -47 155 - 10, 20 25
NaOH 40 2.1 318 1390 2 33 26, 37, 39, 45
HCl
36.46 1.06 -40 84 3 34, 36, 37, 38 26
Adipic Acid 146.14 1.36 151-153 338 - 36 2
Equipment reflux: vac. filtration:
Preparation
Substance eq n (mmol) V (mL) m (g) KMnO4 1.911 58.09 - 9.18
Cyclohexanone 1 30.40 3.14 - H2O solvent - 75 -
Experimental section 9.18 g potassium permanganate was added in a two neck round bottom flask and dissolved in 75 mL water. While stirring, 3.14 mL cyclohexanone were added and the solution was heated to around 30 °C. Than 20 drops of a 10% NaOH solution were added and the temperature was raised to 50 °C for about 20 min. After this the temperature was raised to 100 °C for about 5 min. Then it was cooled down to RT, filtered, washed with cold water and acidified with HCl until the pH was 0. The Solution was put in an ice bath and the resulting white crystals were collected and dried in vacuum desiccator for a week. Then they were characterized. Yield
V m n Yield - 1.14 g 7.801 mmol 25.7 %
Characterisation Melting point 149.4 – 150.7 °C (lit. 151 – 153 °C) Peaks in IR spectrum 2961 cm-1 sat. OH
1684 cm-1 C=O 3200 - 2500 cm-1 wide, COOH Discussion The characterization of the product showed the right results for the IR spectrum and the melting point. But I didnʼt get so a good yield. Maybe because I washed it out with some water before acidification with HCl.
Literature http://chemfinder.cambridgesoft.com/ http://www.chemexper.com/ http://www.wikipedia.org/ http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi Attachment
- Reference IR spectrum - IR spectrum - Copy of the lab notebook
Reference IR spectrum http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi